Bystander effects have been proposed as a third action pathway of ionising radiation besides direct and indirect effects. The purpose of the study was to investigate whether expression of interleukin-1alpha (IL-1alpha) and beta1-integrin is elevated in bystander cells as a marker for bystander effects in comparison with classical markers such as the clonogenic assay, apoptosis and the presence of micronuclei. The hybrid cell line E.A. hy.926 obtained by fusion of HUVEC cells with the epithelial cell line A 459 was irradiated with 0-5 Gy. Bystander effects were established via medium transfer at 45 min and 4 h after irradiation from irradiated to nonirradiated cell populations. In order to exclude effects of the irradiated medium itself, irradiated medium only was also used for transfer to nonirradiated cells. Then, cells were fixed at 1, 2, 6, and 24 h after irradiation or medium transport and IL-1alpha and beta1-integrin were detected and evaluated. A higher number of beta1-integrin-positive cells was observed in both irradiated and bystander cell populations than in the control group at 1 and 24 h after irradiation with 1 Gy or medium transfer. Significantly higher numbers of IL-1alpha-positive cells were found at 1, 2, and 6 h after irradiation with 1 Gy or medium transfer as well as at 2 and 6 h after irradiation with 5 Gy or medium transfer. Clonogenic survival decreased dependently on the dose in irradiated cells but did not show any significant difference between the bystander cell populations and sham-irradiated cells. The irradiated medium itself did not have any effect. It is concluded that beta1-integrin and IL-1alpha expression may serve as more sensitive markers of post-irradiation responses in bystander cell populations than the classical radiobiological markers. Moreover, overexpression of beta1-integrin and IL-1alpha may induce increased susceptibility to inflammation of bystander cells.

中文翻译：

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Beta1整合素和IL-1alpha表达作为受辐照细胞培养基的旁观者效应：初步研究。

已经提出了旁观者效应作为除了直接和间接效应之外的电离辐射的第三种作用途径。这项研究的目的是调查与经典标记（例如克隆形成测定，凋亡和是否存在白细胞生成素）相比，作为旁观者效应的标记物，旁观者细胞中白介素-1α（IL-1alpha）和β1-整联蛋白的表达是否升高。微核。通过HUVEC细胞与上皮细胞系A 459融合获得的杂交细胞系EA hy.926用0-5Gy照射。通过照射后45分钟和4小时从受辐照的细胞群体转移到未辐照的细胞群体，可以通过介质转移建立旁观者​​效应。为了排除辐照介质本身的影响，也仅将辐照介质用于转移至未辐照的细胞。然后，将单元格固定在1、2、6 照射或介质运输后24小时，检测并评估IL-1α和β1-整联蛋白。在用1 Gy或培养基转移后1和24小时，受辐照和旁观者群体中观察到的β1-整合素阳性细胞数量均高于对照组。在用1 Gy或培养基转移照射后1、2和6 h，以及在用5 Gy或培养基转移照射后2和6 h，发现大量的IL-1alpha阳性细胞。克隆形成的存活率取决于辐照细胞的剂量，但在旁观者细胞群体和假辐照细胞之间未显示任何显着差异。辐照的介质本身没有任何作用。结论是，与经典的放射生物学标记相比，在旁观者细胞群中，β1-整合素和IL-1α的表达可能是更敏感的辐射后反应标记。此外，β1-整合素和IL-1α的过度表达可能会导致对旁观者细胞炎症的敏感性增加。